One-third amazing, one-third good, and one-third awful, Bubba Sparxxx's third CD, The Charm, is a frustrating missed opportunity. The white rapper is insanely talented his drawling flow stays loose and casual even as he's spitting taut verses. And when content and groove dovetail on the blue-collar lament ''Ain't Life Grand,'' he's an A-grade artist. But tired crunk tracks like ''Ms. New Booty'' keep the self-proclaimed country boy from getting his blue ribbon.